Taking care of an infant with a foot injury?

While carrying my son the other night, I tripped. I was trying to maneuver to avoid falling and potentially hurting him, but when I did, I managed to hurt my ankle. I can’t walk more than a few feet without excruciating pain and then my leg goes numb from my knee to my toes.

My question is: does anyone have tips or ideas for taking care of a 4 month old and getting around with him until it’s healed? I’m a single mom and would have better luck teaching my dog to do calculus than getting someone to help me out. I can’t really carry him and use crutches at the same time.